Heart & Cardiology/Second Degree AV Block
QUESTION: I am a 63 year old male, recently referred to a cardiologist because my internist discovered a PVC on my annual EKG. The cardiologist ordered a 24 hour Holter monitor. The results reflected the PVC, but also a second degree AV block ( Wenckebach). The cardiologist said this should be monitored every 6 months, but no further action at this time. If it progresses, he did say a pacemaker would be an option. Otherwise,he prescribed Lipitor 10 mg for a slightly elevated cholesterol. I have no symptoms related to the Wenckebach, but I am worried. Any insights or opinion on this would be appreciated!
The approach of your cardiologist is the one that is currently recommended in most asymptomatic patients with Wenckebach. Patients with symptomatic bradycardia and Wenckebach certainly warrant pacemaker implantation.
Natural history studies suggest that in younger asymptomatic patients (<45) that Wenckebach is relatively benign. In older patients, who are not athletic, the presence of Wenckebach is a risk marker for progression to complete heart block and therefore monitoring for development of symptoms or worsening block is warranted. In certain patients, with high risk EKG features the use of electrophysiological study to determine the site of block may be beneficial. This would have been determined by your cardiologist who will use clinical judgement to managing each case. As in your case, the majority of asymptomatic patients in a similar situation will undergo periodic surveillance.
Hope that was helpful,
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QUESTION: Thnak you very much for the reply. When you stated that in older patients who are not athletic, the presence of Wenckebach is a risk marker for progression to complete heart block... I walk between 3-4 miles day and exercise on an elliptical machine 45 minutes daily, 6-7 days/week. Would I be considered "athletic" or not? Is it possible I have had Wenckebach since I was a young man and never knew it since I never had a Holter monitor before? What percentage of Wenckebach patients progress to needing a pacemaker? Thanks again!
In terms of athletic, i don't think (although its possible) the level of exercise you do would result in a high 'vagal tone' that would lead to exacerbation of heart block although whats reassuring is that you are able to exercise to a good degree without symptoms.
A good way to think of it is as follows. People with Wenckebach have a higher risk that the general population of complete heart block, however the actual risk is relatively low. Its difficult to give exact numbers as it all depends on your risk category. In people with underlying heart disease such as significant coronary disease or heart failure the risk is higher, whereas in those with no underlying heart disease it is thought to be low, probably <10%.
Hope that was helpful,